1. Field of the Invention
The invention relates to pressure vessels and more particularly to a pressure regulator of a gas cylinder with improved characteristics.
2. Description of Related Art
A conventional gas cylinder is shown in FIGS. 5 and 6 and includes a pressure regulator 90 mounted on a container body 80. The pressure regulator 90 includes a valve body 91 having an upper chamber 911, an intermediate chamber 912, a lower channel 913 communicating with the interior of the container body 80, and a port 914 communicating with the upper chamber 911. The upper chamber 911 communicates with the intermediate chamber 912 which communicates with the lower channel 913.
The pressure regulator 90 further includes a hollow member 92 including an enlarged head 921, the hollow member 92 provided in the intermediate 912 and having a bottom engaged a top opening the lower channel 913; a compression spring 93 put on the shank of the hollow member 92 and biased between the head 921 and the bottom of the intermediate chamber 912; a pressing member 94 placed on the top of the hollow member 92; an externally threaded stem 95 disposed on a top of the pressing member 94; an internally threaded hollow cap 96 threadedly secured to the stem 95 which has an upper portion passes through the hollow cap 96; a knob mounted on a top end of the stem 95 to cover the hollow cap 96; and a coupler 98 having one end connected to the port 914 and the other end connected to a predetermined destination. Pressurized contents in the container body 80 can flow to the predetermined destination via the lower channel 913, the intermediate chamber 912, the upper chamber 911, and the coupler 98.
Operations of the conventional pressure regulator 90 are discussed below. In an inoperative state, the top opening of the lower channel 913 is blocked by the bottom of the hollow member 92 so as to prevent any pressurized contents in the container body 80 from flowing to the destination via the pressure regulator 90. For supplying the pressurized contents in the container body 80 to the predetermined destination, a user may counterclockwise rotate the knob 97 to lift the stem 95 relative to the cap 96. As such, the hollow member 92 moves upward to expand the compression spring 93. As a result, the hollow member 92 moves upward to unblock the top of the lower channel 913, thereby permitting pressurized contents in the container body 80 to flow to the predetermined destination via the lower channel 913, the intermediate chamber 912, the upper chamber 911, and the coupler 98. The flow rate and pressure of the released pressurized contents can be adjusted by the number of rotating the knob 97. After use, the user may clockwise rotate the knob 97 to lower the stem 95 relative to the cap 96 to compress the compression spring 93 until the hollow member 92 moves downward to block the top of the lower channel 913 (i.e., blocking the flow of the pressurized contents).
However, a number of drawbacks are found in the conventional gas cylinder. For example, pressurized contents still exist in the upper chamber 911 after blocking the flow of the pressurized contents. The pressurized contents can damage the components. Further, the components are complicated, thereby increasing difficulties of assembly. Furthermore, maintenance cost can increase greatly.
Thus, the need for improvement still exists.